Do you want to be a scientist?

This month, Living Links is trialing a new Citizen Science game, inviting visitors to participate in some of the exciting research that happens here. Read on to find out more about Citizen Science and how the game works… 

As a research centre, one of our primary goals at Living Links is increasing public engagement with science. That’s why we are launching ‘Living Together’, a new Citizen Science game that allows visitors to collect and classify real life scientific data for our longstanding project about monkey welfare and enclosure use. 

“Citizen Science”, or “Community Science”, is a practice that focuses on advancing knowledge through research done by, for, and with members of the public. It aims to foster a large scientific community as the intersection between public engagement, education, and scientific enquiry. Citizen science projects are great opportunities for volunteers to collect and classify data, improving their awareness of the scientific process and opening avenues for exploration and curiosity of the field.  

The game begins by instructing the participants through various phases of ‘Citizen Scientist Training’. This includes a manual of the different monkey species here, the 5 different zones of the enclosure, and a variety of monkey counting freeze frames where visitors will be challenged to use their keen scientific eye to spot monkeys in each zone (Figure 1).

Figure 1: The different zones of the enclosure.

Following our Training, our newly fledged scientists note down in real time how many capuchins and squirrel monkeys are present in each of the 5 zones. The data and feedback collected from this trial phase will help us improve the final version of the game, in which this extensive numerical data will be analysed by our researchers. This data will reveal where each species prefers to spend time throughout the day, providing researchers and keepers with the knowledge needed to improve the welfare, enrichment, and habitat of these primates. 

We hope that this game can help visitors to gain a newfound connection with research, helping them to feel empowered and engaged with science. If this sounds interesting to you, we hope you stop by!

Written by: Emma Hearn

Serious Fun at Living Links!

Back in April, Living Links hosted an exciting Primate Pop-Up as part of the Edinburgh International Science Festival. Read on to hear about the importance of play, and how zoo visitors took part in an experiment investigating how monkeys learn through play.

Learning through Play

Play is a big part of human life, especially in childhood. It is also a behaviour found in many other animal species. The fact that play is found across the animal kingdom suggests that it must be a valuable behaviour for survival: if it were not advantageous in some way, it would not have evolved. So, the question is – why do we play, if not just for fun?

Right about now you may be wondering what exactly play is. This is a good question – one that comparative researchers have been struggling to answer for years, as common definitions of play tend to be human-centred. Graham and Burghardt (2010) developed a set of criteria that can be used to identify play in any animal species. Play behaviour (1) has no obvious purpose; (2) is enjoyable, rewarding, or spontaneous; (3) is different from day-to-day behaviours (for example, play fighting is more exaggerated than real fighting); (4) is done repeatedly; and (5) is done when relaxed.

Research at Living Links is exploring the idea that that one of the biggest values of play is that it helps us to learn. Children will play when there is something to find out – when they are curious. In a 2011 experiment, researchers gave children a toy that lit up and played music only when specific beads were placed on it. Children tested each possibility in turn, and if two beads were stuck together, they would turn the beads on their ends to try them out one at a time. This behaviour is very similar to how scientists devise experiments! Just through exploratory play, the children were able to learn and remember how the music box worked.

Figure 1: The Living Links monkeys investigating openable versus un-openable objects.

Learning Through Play at the Primate Pop-Up

Animals also like to play around with objects: look at the Living Links monkeys investigating objects that are openable versus un-openable (Figure 1). They played around with the objects in various ways: hitting them and banging them, spinning them around and even roly-polying with them! When they were later given the chance to come into the research rooms, then knew which objects were easy to open and which were difficult. However, even monkeys that did not have a chance to play were pretty good at choosing the right object, so we’ll need to make the task harder in the future!

At the Primate Pop-Up Event, we wanted to observe learning in action, by giving the Living Links monkeys an exciting new resource: crackers! The crackers either contained a jackpot (high value trail mix) or some basic vegetables. We wanted to see if the monkeys were able to learn which resource had high value. Visitors to the pop-up helped create these crackers by filling up cardboard tubes with either low value or high value treats, and then wrapping them in paper. The jackpot crackers were wrapped in black paper, and the basic crackers in brown paper. The monkeys were then given the crackers, while the visitors helped keep track of their selection.

Figure 2: The crackers used in the Primate Pop-Up.

At the beginning, the monkeys were actually scared of the jackpot crackers! This is because they were not used to the black paper and were suspicious of the novelty. So early on in the afternoon, monkeys only chose the basic crackers. However, they eventually decided to explore the black crackers, leading to an even split of choices between the two cracker types. When the same experiment was carried out on the second day of the event, there was a clear preference for the black crackers. This suggests that the monkeys learned which resource had a higher value, just through playing with them!

The results of the Primate Pop-Up experiment showed just how quickly monkeys engage with their environment and learn about it.  We also spent time with the children that visited on the day talking about a future experiment in which we could look at how monkeys learn even when there isn’t any feedback (like food rewards). You can see some of their suggestions in figure 3.

Playing can be a way of conducting informal science experiments, by trying out new behaviours and manipulations and seeing what happens. This helps build up new skills, like tool use and problem-solving. Though traditionally we might think of play as without a real purpose, the research continues to prove this idea wrong – it seems that play is some serious fun!

Figure 3: Some of the kids’ suggestions for future experiments investigating learning through play.

 

 

First Impressions- a research intern’s view

Written by: Wilson Chen

Hello, and welcome to the Living Links Blog! My name is Wilson, I am a second-year psychology student at the University of St Andrews. I am currently working in a public engagement with research internship at Living Links. I was interested in an internship at Living Links because I wanted to learn more about the role of monkeys in the study of behaviour and cognition. Moreover, I believe that bridging the gap between psychology research at Living Links and the visitors at Edinburgh Zoo is a meaningful endeavour that can promote and educate the public about psychology as a scientific subject.

Starting a new internship in a zoo can be both exciting and nerve-wracking. I may have been looking forward to this opportunity for a long time, but it can be hard to know what to expect when you’re stepping into a new environment with new people and animals. In this blog post, I will talk about my first impression of the centre and share some of my experiences talking to visitors during my first weekend as an intern.

            Originally, I thought the first thing I was likely to notice was the smell. The smell of monkey enclosures can be quite striking, as primates have strong body odour and produce a lot of waste. However, I was pleasantly surprised at how everything is clean and tidy at Living Links. The environment on the main platform (which is where I spend most of my time working) is fantastic. I can get a great view of both the east wing and the west wing enclosures. It can get quite chilly sometimes, especially when the wind picks up, but I am sure the weather will be much more pleasant when spring comes around.

            Whether it’s to see the exotic animals or to learn about wildlife conservation efforts, visitors often come with their own expectations and interests, and it is very apparent that most visitors are very engaged with the experience Living Links has to offer. When I approached visitors about doing a visitor feedback survey, many visitors reacted positively. To be completely honest, I thought I was going to get shut down most of the time, but I was happy to be proven wrong. Visitors of all ages can be seen at Living Links, and we see a lot of families. For the children coming with their parents, this could well be their first time learning about scientific research. The Living Links centre could be a great starting point in children’s engagement with scientific inquiry and the nature of science.

            While walking around the place asking people to fill in surveys about visitor experiences, I get a lot of opportunities to watch the capuchin monkeys go about their day. As I started to observe them, I began seeing a lot of similarities between their behaviour and human behaviour. Capuchins are social animals that form complex relationships and have a wide range of emotions. Watching them interact with each other can be very fascinating and heart-warming. You may also be struck by how intelligent they are, as you observe them playing, using tools, and communicating with each other in sophisticated ways. One thing that stood out to me is the similarity between the dietary habits of capuchin monkeys and human beings and how they do a lot of the same things as humans. They will remove seeds from food like bell peppers and skin from chickpeas (I noticed they are particularly efficient at this one). Compared to larger mammals who are often seen inhaling entire pieces of food at once, capuchin monkeys are more advanced in their methods of dealing with food.

            Perhaps one of the most rewarding aspects of interning at Living Links is the opportunity to build an understanding of the monkeys. Obviously, I am not there yet as I can barely recognise a handful of monkeys. But I hope that over time, I will be able to tell them apart, get to know each individual’s unique personality and preferences, and develop a deep appreciation for the complexity and beauty of their lives.

            I am looking forward to the rest of my internship at Living Links and I am sure this will be an eye-opening experience.

Abstract Knowledge: Uniquely Human?

Written by: Anna Redly

A recent study comparing the abilities of 4- to 5-year-old children and the Living Links capuchins found that only the human children were able to make predictions using abstract knowledge.

Imagine that there are two brown paper bags in front of you. You know that they contain sweets, but not what kind. You reach into the first bag and pull out a handful of four green gobstoppers. You then reach into the second bag and draw out four chocolate buttons. After just taking four sweets from each bag, you can make a reasonable prediction about what kind of sweet you might find if you went in for seconds in either bag: a green gobstopper for the first bag, and a chocolate button from the second bag. This is called a ‘Level 1 Abstraction’. You will also likely arrive at the conclusion that brown paper bags contain sweets of the same kind – this is called a ‘Level 2 Abstraction’. You would only need to take one sweet from a third bag to predict that all the other sweets in the bag will be the same kind.

Abstractions represent generalised information that is common across different situations, like in the sweet example. This ability is central to the way we humans navigate the world, helping us to learn quickly from limited information and make predictions in new situations. The questions that Felsche and colleagues wanted to investigate were how early human children develop this ability and whether it is an ability that we share with other primate species.

To explore this question, Felsche and colleagues designed an experiment with a similar principle to the sweet example. The researcher would sample items from three containers, which contained sticker strips for the children and food for the monkeys. There were two experimental conditions. In one condition, the sampled items supported the idea that items were sorted into containers by their type (e.g., four apple pieces from one container and four raisins from another). In the other condition, sampled items suggested that items were sorted into containers based on size (e.g., four small items of different types from one container and four large items of different types from another). After exposure to one of the two conditions, the participants were then presented with two new containers and an example item from each and were prompted to choose from which container they wanted to receive their next item. 

Diagram 1: Experimental Conditions

In both conditions, the two example items were always a small but high-value item from one container, and a large but low-value item from the other container. The prediction was, that when the children and monkeys were in the type condition, they should choose the next item from the container with the high value example item – so that they can get a high value item too. In the size condition, one high-value sample does not guarantee that the rest of the items in the container will be high-value, as items are sorted into containers based on their size rather than type. If the participants recognised this, they would choose the large and low-value option because no matter which food type will be next, they at least can secure another big item, which is always better than a smaller one.

The researchers found that the capuchins choices of test containers was at random and not influenced by whether they had previously seen that treats are sorted into containers based on their size or their type. This performance suggests that the monkeys did not learn about the abstract rules determining food distribution patterns across containers. The children, however, chose the hidden sample linked to the small high value item more often in the type condition compared to the size condition. This sensitivity to the experimental condition suggests that the children were able to generalise at the second level of abstraction and make predictions accordingly.

The researchers then designed a second experiment, to see if the capuchins were able to form Level 1 Abstractions within this paradigm. In this experiment, like in the sweet example, the monkeys and children were presented with only two containers from which four evidence items were sampled, respectively. Like in experiment 1, there were two experimental conditions (type and size), but this time the choice items were sampled directly from the original containers, so no generalisation to new containers was required.

Again, the capuchins performed at chance level in both conditions, suggesting that they are unable to form Level 1 Abstractions. The children performed above chance in the type condition, but seemingly at random in the size condition. This is interesting, implying that while children can use Level 1 and 2 Abstractions to inform predictions, this ability might depend on the item characteristic they form generalisations about (e.g. type or size). However, the researchers also ran a computational model based on the children’s and monkeys’ preferences. This model suggested that the children’s above chance performance in the type condition could be due to the fact that they simply cared more about their reward’s type than its size.

This study has extended our current knowledge of abstract knowledge formation in non-human species and provided a novel task design that can be altered to learn more about the abilities of different species – both contributing to the investigation of whether humans are indeed unique in our ability to use abstract knowledge.

Want to know more? Click here to read the paper!

What is Living Links? Click here to learn more.

‘The Stork’ Comes to Visit the Living Links Squirrel Monkeys!

Written by: Dr. Blake Morton

We are very excited to announce that over the summer, four of our squirrel monkeys in West Group – Gerda, Jasmine, Orla and Toomi – each gave birth to a brand new beautiful baby, marking the most recent addition to our primate family tree here at the centre. Those of you who visited Living Links over the summer might have noticed these adorable yellow “fur balls” darting around their enclosure (with their mothers not far behind, trying to keep up!). The recent births have given researchers and staff an exciting opportunity to learn more about squirrel monkey behaviour. Here are some interesting facts about squirrel monkey infant development, along with videos of the new babies with their mums (click on the links to play)!

Within the lifetime of a squirrel monkey, which is roughly 25 years in captivity, a female can give birth to as many as 10 or more individuals. Typically, females reach adulthood around the age of 2 ½ years, and become pregnant soon after (usually by the alpha male of their group). After a gestation period of around 147 days, pregnant squirrel monkeys finally give birth to a single baby. Most births take place at night, and labour usually lasts around 1-2 hours.

Two of our mothers – Gerda and Jasmine – are over 15 years old, and are the oldest and most prolific matriarchs of their group. Collectively, these two mums have given birth to an impressive 13 monkeys, or roughly 70% of West Group! Orla and Toomi are 6 and 11 years old, and the daughters of Gerda and Jasmine, respectively. Although less experienced than their mums, with Orla having raised 3 babies so far and Toomi having raised 2, they have their mums there for guidance.

Like human infants, baby squirrel monkeys are born with limited motor coordination which, along with their eyesight, improves over time. As you can see in the following video, during this vulnerable stage of development, the babies learn to move around and explore their environment from the safely of their mums’ backs.

Exploring

Baby squirrel monkeys initially cling to the stomachs of their mums following birth, which as you can see in the video below, makes it easier for suckling. Eventually, the mother will move the baby to her back, where the baby will cling until the next time it needs to nurse. But don’t worry, baby squirrel monkeys have a strong grip to keep from falling while their mums jump between branches!

Nursing

After about 2-3 weeks, the babies will start to eat solid food particles that they find on their mother’s fur (that is, if she’s a messy eater!), or, as you can see in the video below, by cheekily stealing food directly from mum’s hand! Baby squirrel monkeys will continue to nurse from their mothers up until about 6 months of age, after which they are completely weaned and learn to find food on their own.

Scrounging

The four new babies seem to be growing quicker by the day. Now that we’re mid-way through November, each baby is showing signs of becoming increasingly independent. They nurse less, and instead eat more solid foods, like fruit, seeds, insects, and vegetables. As you can see in the video, they spend the majority of their time playing, exploring their environment, and climbing branches all by themselves.

Independence

Despite their growing independence, at the end of each day, both baby and mum will come back together to curl up and sleep. As you can see in this video, however, mum always keeps a watchful eye to protect her little ‘bundle of joy’. Clearly, a mother’s job is never done!

Tired mums

“Cup Game” Provides Insight into Monkeys’ Understanding of Hidden Objects

Written by: Dr. Blake Morton

Some of you may have seen or heard about our capuchin and squirrel monkeys participating in a special type of problem-solving task, which we’ve affectionately dubbed “the cup game”. This task is designed to measure object permanence, which is a fancy term psychologists’ use to describe why an individual knows that when an object or person goes out of sight, that object/person still exists (i.e. it hasn’t fallen off the face of the earth!). In humans, this mental ability has fully developed by around two years of age, which is why children younger than this typically find the “peek-a-boo!” game hilarious: when you cover your face with your hands, children who have not yet developed object permanence think you’ve disappeared, which is why they act surprised as you “magically” reappear and say “peek-a-boo!” with a grin. It’s a classic stage in child cognitive development.

We’ve known for quite some time that monkeys and other animals like dogs and birds have this ability too. Not surprisingly, this ability should exist in many different kinds of animals where, for example, individuals foraging in trees might benefit from understanding that hidden food items are behind branches and leaves, or that predators concealed by tall grass are still lurking nearby!

We use the cup game at Living Links to train new researchers who come to work with our monkeys. The task is fun and easy to administer, and it gives the monkeys and new researchers an opportunity to get to know one another! Have a look at one of our squirrel and capuchin monkeys participating in the cup game below.

Squirrel Monkeys Cup Game Video

Capuchin Monkeys Cup Game Video

As you can see in the videos, monkeys must choose between two different cups. One cup has a hidden food reward underneath it, the other cup does not. Each monkey gets the chance to play the game twice a day, once in the morning and then again in the afternoon. Within each of these sessions, monkeys can get up to ten food rewards if they choose the correct cup every time. The monkeys’ behaviour suggests that they possess object permanence because they always reach for the cup containing the hidden food reward, even when the position of each cup has been switched. A simple task, but it is clear that object permanence exists in these species – just like us!

 

Do Capuchin’s deceive their con-specifics with false alarm calls?

Written by: Kirsty-Marie Moran

Have you ever involuntarily screamed at a scary movie? Ever wondered why you couldn’t control it? Well, the underlying cause of this spontaneous vocalisation that draws all attention to you in that split second is emotion. This lack of control over some of our emotions is not unique to humans, we also share this with other species such as nonhuman primates. Primates may not scream at a scary movie when scared or startled but they do produce an alarm call when a threat is near by, communicating this message to their group mates. 

However, emotions do not always result in involuntary vocalisations, they can somewhat be controlled and used to your advantage, for instance, as a child if you cry because you did not get what you wanted and your parents give in then you learn to use those ‘crocodile tears’ to get what you want. This deceiving behaviour is something that primates such as chimpanzees also do in certain contexts

When competing for food, chimpanzees can produce a false alarm call, tricking others into thinking a threat is nearby which gives the calling chimpanzee an opening to go get food first. Up until recently, this deceptive behaviour has been limited to species with high cognitive abilities. However, recent evidence suggesting high cognitive abilities are not necessary for this deceptive behaviour has led to the belief that maybe smaller primates, such as brown tufted capuchins can also deceive their fellows, much like chimpanzees do.

This led to an important research question, ‘can Capuchins use alarm calls to deceive conspecifics or are these calls a product of involuntary emotion?’

One of our researchers at Living Links alongside researchers from German, Italian, and UK universities set out to answer this question by focusing on the occurrence of anxious behaviours i.e. scratching when these false alarm calls were produced by capuchins.

The researchers placed banana pieces on wooden platforms (figure 1) to stimulate food competition and elicit the ‘deceptive’ calls in wild black Capuchins at Iguazu National Park, Argentina. It was predicted that if anxiety drove the false alarm calls, then anxious behaviours and ‘deceptive’ alarm calls would happen together. Additionally, brown tufted capuchins at the Institute of Cognitive Sciences and Technologies in Italy were observed to check if their alarm calls and anxiety more generally occurred at the same time.

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Figure 1.

During the platform experiments in the wild, it was found that those who gave alarm calls displayed a lower level of anxiety. Whilst those who gave alarm calls in captivity displayed higher levels of anxiety. These findings suggest that anxiety was a reliable indicator of predator alarm calls, but that anxiety alone does not fully explain this phenomenon.

Overall, it was concluded that anxiety is necessary for the call to be produced, but some form of intentional control ultimately decided whether they would call or not. This suggests that it is unlikely these monkeys intentionally trick their group mates, but that they are driven by emotion and possibly associative learning.

 

 

Kean, D., Tiddi, B., Fahy, M., Heistermann, M., Schino, G., & Wheeler, B. C. (2017). Feeling anxious? The mechanisms of vocal deception in tufted capuchin monkeys. Animal Behaviour, 130, 37-46. doi:10.1016/j.anbehav.2017.06.008

Understanding primate feelings through their personalities – a keeper insight.


Written by: Kirsty-Marie Moran

Personalities come in all shapes and forms, contributing to what makes you different from another person. It is also an intriguing aspect of ourselves that we share with our primate cousins. We can ask each other if we are well but with animals, this is not so easy. It is each individual primate personality that could be the key to understanding how primates feel and because we are unable to ask how they feel, we can only observe and record what we see. 

There are several ways in which researchers have attempted to answer questions on how primates feel such as taking blood samples, measuring hormones, or sitting observing behaviours.

However, in a recent study at the National Institutes of Health, Georgia State University, the researchers asked for the help of the keepers – after all, many of them have spent years with these animals. Who would know the personalities of the primates better?

Positive allo-grooming. Known to strength the relationship between the giver and receiver.
Positive behaviours. These brown capuchins are engaging in some allogrooming.

Using a questionnaire based on studies of people’s happiness it has been possible to assess happiness in nonhuman primates. With many studies suggesting the results are similar to that of humans. In humans, happiness and welfare are directly linked and the study at Living Links attempted to assess welfare and subjective well-being (SWB) in brown capuchins. In doing this they aimed to determine if happiness and welfare are directly relatable in capuchins.

It was found (between 10 keepers and over 200 ratings completed), that there was a high agreement on the capuchins welfare. Finding no difference between SWB and welfare ratings, which suggests that like humans SWB and welfare are linked. Also, any low ratings of SWB and welfare ratings were found to be associated with the display of stereotypic behaviours (i.e. self-grooming), indicated that a questionnaire which took on average 3minutes could be a quick and reliable form of studying welfare.

This may change the way welfare is studied in the future. With findings such as these, it may be worthwhile incorporating SWB and welfare related questionnaires into any welfare related research in the future. Especially when you are lucky to have keepers who have spent considerably longer with these animals than the researcher (in most cases) has.

 

Reference:

Robinson, L. M., Waran, N. K., Leach, M. C., Morton, F. B., Paukner, A., Lonsdorf, E., Weiss, A. (2016). Happiness is positive welfare in brown capuchins (Sapajus apella). Applied Animal Behaviour Science, 181, 145-151. doi:10.1016/j.applanim.2016.05.029

The effect you as a ‘visitor’ have on squirrel monkeys.

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Written by Kirsty-Marie Moran and Zita Polgár

Ever wondered if the animals at the zoo notice your presence? And if they do, if they mind you peering in on them?

These are very important welfare questions with many zoos attempting to answer them, including our very own here at Living Links Research Centre situated within Edinburgh Zoo. A recently published paper in the American Journal of Primatology details the results of a study examining the ‘individual differences in zoo-housed squirrel monkeys’ reactions to visitors, research participation, and personality ratings’. The study tackles the important question on whether monkeys with different personalities react differently to visitors, as well as how the size of the visiting groups influences their responses. Understanding individual differences is important because it can improve the animals welfare by catering to each individual’s needs.

During the study, the researchers recorded how long the monkeys spent by the observation window when there were small groups of visitors, large groups or no visitors. They found that the monkeys spent more time up at the window when there were large groups of visitors than when there were small groups or no visitors at the observation window. Specifically, the researchers found personality differences between the monkeys. Those who scored higher on playfulness and scored lower on cautiousness, depression and solitude were more likely to be at the window when there were visitors there.

These results suggest that zoo visitors do not have a negative impact on the squirrel monkeys but rather have a positive impact. Zoo visitors appear to be a form of enrichment, especially in those monkeys with social personalities.

The researchers speculate that the squirrel monkeys at the centre have developed this response due to a number of factors, namely that they are provided with a variety of enrichment opportunities. They frequently have positive interactions with a variety of humans through voluntary research studies and they have the option to choose from five different enclosure areas with different levels of exposure to zoo visitors.

 

Reference

Polgár, Z., Wood, L., & Haskell, M. J. (2016). Individual differences in zoo-housed squirrel monkeys’ (Saimiri sciureus) reactions to visitors, research participation, and personality ratings. American Journal of Primatology. doi:10.1002/ajp.22639

 

Living Links changing the way animal social cognition is measured. Are photograph measures reliable?

Kirsty & BlakeWritten by Kirsty-Marie Moran & Blake Morton with thanks to Alaina Macri and Christoph Voelter.

 

 

I think we could all agree that seeing a photo of a person or place is different to seeing that person or place in real life…right? We react differently to photographs. For instance, if there was a picture of your boss, this wouldn’t stop you checking your private emails, would it? But if this person was there, it might. So, recording the behavioural responses to a photograph in humans, couldn’t possibly be representative of how humans would react to the real-life scenario.

However, this is exactly what is happening when measuring responses to photographs in primates. Scientists often use photos to test how animals perceive the world around them. For example, to test whether a dog can tell the difference between a happy versus sad person, they might record whether the dog whimpers more when it sees an image of a person crying versus laughing. Scientists can use photos instead of real-life stimuli to study animal behaviour because they’re cheaper and easier to bring into the lab. But in the absence of depth, smell, and movement, most animals can likely tell the difference between a photo versus the real thing. Behavioural responses to photos are interpreted to reflect how the primate would react in the real-life situation. Thus, recording how animals react to photos may not necessarily tell us how they would behave towards the same scenario in real life. Surprisingly, very few scientists take this problem into consideration when interpreting animals’ responses to photos.

In a recent collaborative study between Living Links and the Language Research Center of Georgia State University, Morton et al. (2016) investigated for the first time whether brown capuchin monkeys react to photos of the alpha male of their group (see below) in the same way as they do in real life.

LL morton experiment picture

Typically, lower-ranking capuchins react to the presence of an alpha male by either avoiding them or acting submissively in their presence (e.g. letting the alpha have first dibs on food). By placing food in front of a photo of the alpha male and then doing the same but in front of the real-life alpha, the researchers were able to compare whether the monkeys’ behaviour towards the photo could predict what would happen in reality.

The researchers found that the capuchins did not react to the photo in the same way as they did to the real-life alpha. Thus, a picture of their “boss” (the alpha male) did not fool the monkeys, let alone prevent them from grabbing the food next to the photo.

This study provides scientists with an important cautionary note when using photos to study animal behaviour.

Morton, F. B., Brosnan, S. F., Prétôt, L., Buchanan-Smith, H. M., O’Sullivan, E., Stocker, M., Wilson, V. A. (2016). Using photographs to study animal social cognition and behaviour: Do capuchins’ responses to photos reflect reality? Behavioural Processes, 124, 38-46. doi:10.1016/j.beproc.2015.10.005